That's w/ the 2tbs aquarium salt and 2tsp melafix. I have a filter that currently only has somekind of weird thing it calls a bio-scrubber, box says it "cultivates aerobic bacteria, eleminating toxic ammonia, and nitrites before water cascades back into aquarium". Its a Tetra Whisper 40I. Took out the carbon bags like the Metafix bottle said. But she has lost her previously voratious appetite. She used to get very excited when she saw the food bag, now she just hides. Is this normal? I have 2 pieces of rock in there for her(its clean). No substrate. Just 2 big rocks.